The Concept of Sanity
by marian93
Summary: "After two years of loneliness, the concept of sanity can become… very flexible, Sherlock."


_**A/N: **This is a little ficlet based on Estherlune's amazing gifset on Tumblr. Go see it:_

_ post/61855638508/sherlock-au-after-two-years-of-lo neliness-the_

_Written for Shannon (magickbeing) cause it was her birthday and she's made of 174 kinds of awesome and we both freaked out over that gifset. _

_**Warnings**: Gore, violence, really Dark!John, mentions of suicide._

_**Disclamer**: Don't own anything._

* * *

**The Concept of Sanity**

John was eight the first time he killed something.

It was a pigeon. He'd had a slingshot and perfect aim, even at that age, and the bird had just been sitting there, on that fence. The stone hit it right in the eye, and it flopped miserably to the ground.

John picked it up, examined it, got blood on his thumb. He pressed at the wound, felt the tender tissue give. He plucked the feathers out of the wings and then pulled at them. Pulled and pulled until they separated from the pigeon's body with a crunch.

Then he cried.

He decided to become a veterinarian to make up for it, for the horrible thing he had done. Later, he chose to be a doctor instead, to make up for the thoughts that sometimes crept into his head and made him sick to his stomach_._

* * *

John was twenty-six when he first killed a man.

It was in self defense. The bullet cut smoothly through chest muscle and sternum. Blood rose up the man's throat and poured down his chin. John stared at him as he died, at the crimson soaking into the collar on his shirt, at the wide eyes looking back at him until they were sightless. John stared at the coagulating blood, stared and stared until one of his men tackled him to the ground just as a bomb went off to their right.

That night John had his first nightmare. He was cutting off the man's arms just like he'd torn off that pigeon's wings. He threw up upon waking, heart pounding and a thrill running down his spine that he savagely labelled as disgust.

* * *

John was thirty-nine when he decided to kill himself.

He stood on a familiar rooftop and looked down—imagining he was a bit taller, a lot smarter, trying to picture what _he'd _seen last. Trying to figure out why_ he'd_ chosen this place, why _he'd_ bothered calling. John knew what happened when a human body hit the cold cement after falling from that height. He knew all the lovely—_no! no_—ways the body could break. He was a doctor, he'd seen his fair share of inside bits on the outside, skin loose and peeled, skulls like pie crust, flaky and floating on mush that was never meant to touch another human's fingers.

He knew all the curious things that had happened to Sherlock when he fell—no, _jumped_. He'd jumped. Sherlock had known that John _knew_, and he'd jumped anyway. Sherlock had known—_he had to have known_—that John's brain would make sure to replay all his detailed knowledge of human anatomy and apply it to his best friend's corpse. John didn't need to read the autopsy report to know how much of the mess on the sidewalk was blood, how much was cerebrospinal fluid, how much was bits of that brilliant brain…

John's breath hitched around a sob, the wind drying his tears before they left his eyes.

He felt nauseous. Sick and wrong all over. Wrong in the flat, wrong at work, _wrong_ inside his head. Wrong, the way his hands stopped shaking every time he thought about Sherlock's blood streaking his pale face. It was a work of art, the contrast. John suppressed another sob, shame churning slow and tight in his stomach.

He stayed on the rooftop for another hour, replaying the scene in his head. It hurt, everywhere at once, and it sickened him.

He didn't jump.

* * *

On his fortieth birthday, John gave up.

He got thoroughly drunk and thought about the sound bones made when they broke.

He smiled himself to sleep.

* * *

Hate was a beautiful thing.

Not red and hot, like mere anger. No. Hate burned cold. It was crisp and white, like a winter morning.

Still, John had found he liked contrasts. Dark scarlet over snow, deep purple over fleshy beige. Capillaries painting the sclera pink. The body had a wonderful array of colors. John liked to watch them flourish under people's skin.

This skin, in particular.

Oh, how he adored this. This _hate. _It was intoxicating, empowering… _Incandescent_, like a blue flame. Wasn't that how people described love? He could believe it, the way his blood rushed and his skin tingled. The way he could _breathe _again just from the thought of it, the thought of painting that pretty face again and again.

He could believe this was love.

"I'm home, dear!" John called out into the dark basement, peering down the flight of stairs. The light from the sole lamp barely illuminated the space. "Did you miss me?"

Every step creaked on his way down, a deliberate decision. It was particularly rewarding when the body on the cot shivered with every second creak. John shivered for entirely different reasons.

He came to a stop at the foot of the dirty mattress, watching as the figure tried, unsuccessfully, to lift itself up from the pool of blood on the sheets.

"I missed _you_, honey," John singsonged, tilting his head to the left and admiring the red string that stretched from a swollen, busted lip to the soiled bed sheet. In a flash, John was lurching forward and grabbing the man by his long neck with both hands. He brought the lolling head closer, so close he could smell the tangy scent of blood and spit and sweat. Something hungry and dark growled inside John and he bared his teeth as he hissed. "For two fucking years."

There was a wet sound and a dribble of blood, an Adams apple moving against a cold palm, two pale eyes—one glassy, one nearly swollen shut—staring at a man they no longer recognized.

John smiled, let go, watched the bruised body fall forward without his support, fall all the way to the floor. It was poetic, watching Sherlock fall. It felt like home.

"But lets not dwell on that," John continued, taking a step back, savoring the younger man's groan and his failed attempt to roll onto his back. John's shoes clicked on bare concrete as he walked around the fallen genius. "You're back, aren't you? It's all that matters. _It's all fine_," he drawled the last three words, a mocking twist on a promise made so long ago.

There was silence, save for ragged breathing from the pale man on the floor. John recalled a few well-placed blows to the sixth and seventh ribs, and felt a familiar flutter of excitement in his stomach for the pretty bruises that would have formed under the ratty, sleeveless shirt. He made a mental note to examine them later, to press on each rib like the keys of a piano and hear the noises he could bring out of his tall, brilliant instrument.

The former soldier stopped in front of those dark curls, matted with blood and grime and hanging in clumps over Sherlock's forehead. He leaned down and grabbed a handful, reveling in the whimper he caused as he pulled. And he kept pulling, dragging the broken detective on the floor, across the small space from the cot to the solitary metal chair in the center of the room. The handcuffs were lying on the floor right by it, and John made little work of seating Sherlock on the chair and cuffing his hands behind his back. He made sure they were nice and tight, rubbing against the already raw skin of the thin wrists. "So, where did we leave off?" He asked. "New York, was it? The operation Moriarty had going there, how you _heroically _infiltrated and destroyed it. So very brave of you." Something twisted in John's stomach, that hate flaring and licking up his throat. He backhanded Sherlock across the face, and it felt just as good as it always did.

"Please, tell me more," he added, tone conversational, curious, polite. It had a certain musicality to it, a lilt, and it soothed John. It made everything quiet and nice. _Fun_. It reminded him of another man, small and unassuming, dark eyes dancing with mirth and murder in equal measure, as if one could not be separated from the other. John was beginning to understand. And wasn't that what Sherlock had done it all for? _The Game?_ Well. John could play it, too.

"You'll hit me."

The whispered words brought him back to the present and he crouched in front of Sherlock. Blood trickled down the tied man's chin as he spoke. It was beautiful. "Whenever I talk, you—"

Yes, that was true. John hated that voice, hated his words, hated all the things he'd done while John was burning, alone, losing his humanity strip by strip. It was like being skinned, but it didn't hurt anymore. It was blissfully _cold _now, everything, except for the blood in his knuckles—Sherlock's blood—as he interrupted the words with a fist.

"Oh, but don't let that discourage you. I'm curious," he said. "That's why I got this place, all the way out here, so we could talk in private. No one to interrupt us. And I did it all for you, darling," he stood from his crouched position and ran loving fingers through the hair at the back of Sherlock's head, petting his ear and cupping the side of his face. The bloody side. His thumb grazed the bleeding cut on that sharp cheekbone, pressing into it. The pained moan he received for his troubles was addictive. "The things I do for love."

"You're insane," Sherlock's voice cracked. It was a broken realization, thick with blood and tears. It made John lean down close and grin at the moisture in the pale green eyes.

"After two years of loneliness, the concept of sanity can become…" John paused, pursed his lips, tightened his hand around the other man's face, "very flexible, Sherlock."


End file.
